The invention relates to a laundry-drying appliance having a lint screen and a method for operating such kind of laundry-drying appliance.
Laundry dryers are known in which for clearing away lint particles deposited on a lint screen a cleaning fluid that detaches said particles from the screen's surface and conveys them away therefrom is flushed across said screen. Said cleaning fluid consists of condensate water formed from moisture extracted from laundry during a drying process. A washing tank's fill levels can vary greatly because the amount of condensate water available for washing the lint particles off the lint screen depends on the dryer's respective load and setting. Because of the varying liquid level, with a valve located in a base of the washing tank being open for the same length of time, a varying amount of cleaning fluid for clearing away the lint particles from the lint screen will run out owing to the varying water pressure.
The cleaning fluid will be used also for conveying the lint particles from the lint screen into a repository after they have been cleared away from the screen. The lint particles and condensate water are separated again in said repository through filtering. The volume of lint particles already deposited from previous clearing operations and, briefly, the lint-laden liquid from the one in progress have to be accommodated in the repository during a clearing operation. Backwater that may even cause the lint-laden liquid in the repository to overflow can therein form in the repository.
WO 2008/119611 A1 describes a method and a device for cleaning a component, in particular a vaporizer of a condenser device, as well as washer/dryers or laundry dryers having said kind of device. For cleaning a component, particularly a vaporizer of a condenser device, located inside a process-air circuit of a washer/dryer or laundry dryer, condensate water obtained in the process-air circuit from the drying of damp laundry and collected in a condensate-water tray, is ducted toward a washing tank provided above the vaporizer and dispensed against the relevant component as a gush of water by the abrupt opening of said tank on the exiting side. All the condensate water stored in the washing tank is therein dispensed for cleaning the vaporizer, for which reason the condensate-water tray either has to be dimensioned as very large or the risk of the condensate-water tray's overflowing will have to be accepted.